Liquid chromatography-mass spectrometry: difference between revisions
Diff·revision 4 → 5·08:51, 3 Nov 2024
Difference between revision 4 and revision 5 of Liquid chromatography-mass spectrometry. 5 lines changed; the page grew by 510 bytes.
| Revision 4 — 19:05, 14 Oct 2024 AnalyticalAnnie (talk) split §Principle from §Practical limitations 2,132 bytes ±0 | Revision 5 — 08:51, 3 Nov 2024 DrTitration (talk) add category for method validation 2,642 bytes +510 | ||
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| 11 | The interface is almost always [[Electrospray ionisation|electrospray]], which works directly from flowing solution. This compatibility is what made the technique routine, and it constrains the chromatography: mobile phases must be volatile and free of non-volatile buffers.{{r|fenn1989}} | 11 | The interface is almost always [[Electrospray ionisation|electrospray]], which works directly from flowing solution. This compatibility is what made the technique routine, and it constrains the chromatography: mobile phases must be volatile and free of non-volatile buffers.{{r|fenn1989}} |
| 12 | 12 | ||
| + | 13 | For peptide work its principal use is identity confirmation — establishing that the peak dominating a chromatogram has the expected mass — and characterisation of impurities, since each minor peak carries a mass that often identifies what it is.{{r|usp1503}} | |
| + | 14 | ||
| 13 | == What it adds over either alone == | 15 | == What it adds over either alone == |
| 14 | Chromatography alone establishes that one species dominates; mass spectrometry alone establishes that a species of the expected mass is present. Together they establish that the dominant species has the expected mass, which is a materially stronger statement than either.{{r|aebersold2003}} | 16 | Chromatography alone establishes that one species dominates; mass spectrometry alone establishes that a species of the expected mass is present. Together they establish that the dominant species has the expected mass, which is a materially stronger statement than either.{{r|aebersold2003}} |
| ⋮ | ⋮ | ||
| 16 | Impurity identification is where the combination is most valuable. A deletion sequence appears as a peak of lower mass by one residue; an oxidised species by 16 Da more; an incompletely deprotected species by the mass of the retained group. See [[Resin cleavage]] and [[Solid-phase peptide synthesis]].{{r|usp1503}} | 18 | Impurity identification is where the combination is most valuable. A deletion sequence appears as a peak of lower mass by one residue; an oxidised species by 16 Da more; an incompletely deprotected species by the mass of the retained group. See [[Resin cleavage]] and [[Solid-phase peptide synthesis]].{{r|usp1503}} |
| 17 | 19 | ||
| + | 20 | Tandem operation — selecting a precursor, fragmenting it, and measuring the fragments — adds sequence information and can locate a modification to a residue rather than merely detecting it.{{r|aebersold2003}} | |
| + | 21 | ||
| 18 | == References == | 22 | == References == |
| 19 | {{reflist}} | 23 | {{reflist}} |
| ⋮ | ⋮ | ||
| 25 | [[Category:Mass spectrometry]] | 29 | [[Category:Mass spectrometry]] |
| 26 | [[Category:Chromatography]] | 30 | [[Category:Chromatography]] |
| + | 31 | [[Category:Analytical methods]] | |
| 27 | 32 |